pub fn odd_fibnacci_sum(threshold: u32) -> u32 {
    // 这里写逻辑
    // todo!()

    let mut a = 0;
    let mut b = 1;
    let mut sum_odd = 0;

    while b < threshold {
        // 求奇数
        if b & 1 == 1 {
            sum_odd += b;
        }
        let next_fib = a + b;
        a = b;
        b = next_fib;
    }

    sum_odd
}
